Identifier ( identifier). A distinction is made between simple identifiers ( simple_identifier) and special identifiers ( special_identifier).
<identifier>::= <simple_identifier> | <double_quotes> <special_identifier> <double_quotes> <simple_identifier>::= <first_character>[<identifier_tail_character>...] <special_identifier>::= <special_identifier_character>... <double_quotes>::= "
Simple identifier: reservation
Special identifier: "ADD", "Example_1"
Simple Identifier
<simple_identifier>::= <first_character>[<identifier_tail_character>...] <first_character>::= <letter> | <extended_letter> | <language_specific_character> <identifier_tail_character>::= | <digit> | <letter> | <extended_letter> | <language_specific_character> | <underscore>
Identifiers can be entered in uppercase/lowercase characters. When you specify simple identifiers ( simple_identifier), upper and lower case are ignored, as the system always converts the identifier to upper case letters.
The first character in a simple identifier may not be a digit or underscore ( underscore). Reserved keywords must not be used in simple identifiers.
Special Identifier
<special_identifier>::= <special_identifier_character>... <special_identifier_character>::= <! any characters <character>, that can be linked in any sequence !>
Identifiers can be entered in uppercase/lowercase characters. Special identifiers ( special_identifier) are always used as specified in the database; that is upper and lower case characters are taken into account. Special identifiers are case sensitive.
If the name of a database object is to contain lowercase letters, special characters, reserved keywords, or blanks, the identifier must be specified as a special identifier that is enclosed in double quotation marks ( double_quotes).
Quotation marks within a special identifier are represented by two consecutive quotation marks.
Explanations
<letter>::= A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z <extended_letter>::= # | @ | $ <language_specific_character>::= <! <any letter that occurs in a northern, southern, or central European language and is not contained in the list of <letter>> | <for a UNICODE-enabled database: any character that is not included in the ASCII code list from 0 to 127> !> <digit>::= 0 | 1 | 2 | | 3 | 4 | 5 | 6 | 7 | 8 | 9 <underscore>::= _
Language-specific characters
German umlauts: ä, ö, ü
French letters with a grave accent: →